CD8+ T-cells play a crucial role in eradicating viral infections. The focus of this project is two-fold. First, to study mechanisms that viruses use to subvert CD8+ T-cell responses and second, to understand how primary CD8 + T-cells are stimulated. Despite the importance of T-cells, we do not yet fully understand the induction of a CD8+ T-cell responses and the generation of CD8+ T-cell memory to virus infection. For viruses in which traditional vaccine approaches have not been successful, it is hoped that induction of CD8+ T-cell memory will enhance immunity. To induce optimal CD8+ T-cell responses to vaccines it is necessary to understand how primary CD8+ T-cells are stimulated. This project aims to address the following questions; 1. Following a virus infection in what location are primary TCD8+ cells stimulated? 2. What types of cells are capable of effectively presenting antigen to primary CD8+ T-cells? 3. Is the antigen presenting cell infected, or does it present viral proteins obtained from infected cells? 4. How do the answers to questions 1-3 vary between different antigens, with different viruses, and by different routes of presentation? This year we found that monocytes are uniquely susceptible to viral infection among blood mononuclear cells, with the likely purpose of generating cells with enhanced capacity to activate innate and acquired antiviral immunity.